1. Field of Invention
The present invention relates to systems for cleaning and recycling materials for absorbing hydrocarbons and the like, and in particular to a pollution pad cleaning system for recyclably removing hydrocarbons from an absorbent material such that the material is re-useable as originally designed.
The preferred embodiment of the present invention teaches a pollution pad cleaning system comprising a multi-stage treatment process, wherein polypropylene absorbent pads soaked with waste oil and the like are treated via a system of squeeze rollers, a solvent shower, centrifuge spin, and then drying and fluffing, restoring the pads to a like new, reusable condition. The collected waste oil and solvent are removed at a predesignated concentration from the system for recycling.
While the preferred embodiment of the present invention teaches a continuous system via the utilization of conveyors and the like, and wherein the contaminated pads are placed upon the ingress portion of the system and cleaned, reusable pads are discharged from the exit end of the system, an alternative, working embodiment of the present invention teaches a system comprising a plurality of treatment stations which may be economically configured utilizing a minimum of labor and start-up costs.
The present invention provides an inexpensive, environmentally sound method of treating and recycling pollution absorbing pads. This is in contrast to the past practice when such pads were disposed of in landfills, creating still another pollution problem, and at a disposal cost greater than the cost of implementing the present cleaning and recycling system of the invention.
2. Prior Art & General Background
While the prior art is replete with various designs for oil absorbent materials and the like, none teach or contemplate a system for recycling the materials in a manner contemplated by their use, while recycling the absorbed liquid.
A list of prior patents which may be of interest is presented below:
______________________________________ Patent No. Patentee(s) Issue Date ______________________________________ 4,981,097 Beyrouty 01/01/1991 4,969,774 Arseneeault et al. 11/13/1990 4,965,129 Bair et al 10/23/1990 4,925,343 Raible et al 05/15/1990 4,919,820 Lafay et al 04/24/1990 4,737,394 Zafiroglu 03/12/1988 4,652,372 Threadgill 03/24/1987 4,497,712 Cowling 02/05/1985 4,401,471 Eckardt et al 08/30/1983 4,371,441 Mathes et al 02/01/1983 4,341,637 Smith 07/27/1982 ______________________________________
A review of the prior art reveals that there have been taught in the past various methods of absorbing oil utilizing a variety of materials and systems. However, it will be shown below that none contemplate a system for removing the absorbed hydrocarbons in such a manner as to allow them to be recycled, while allowing the absorbent material to be reutilized in the manner which it was originally intended.
For example, U.S. Pat. No. 4,969,774 issued 1990 teaches the utilization of "pre-cooked and puffed cereals as oil spill sorbents", but does not teach or suggest a system wherein the absorbent materials can be recycled. Interestingly, the disclosure recognizes that absorbent pads can pose environmental hazards once used.
U.S. Pat. No. 4,925,343 issued 1990 teaches a composition containing wood fiber for absorbing oil, but teaches as the only disposal remedy for the hydrocarbon-soaked composition burial or burning.
U.S. Pat. No. 4,919,820 issued 1990 teaches the utilization of mesh containers containing waterfowl feathers for absorbing oil and the like, recognizing that "Reclamation of the oil may be effected by squeezing the container and feathers therein to separate the oil from the feathers, and collecting the separated oil...." It is submitted, however, that once the waterfowl feathers become saturated with oil, their absorption capability will be greatly decreased, and squeezing the oil will not sufficiently remove the contaminants to allow for performance near approaching the first usage.
U.S. Pat. No. 4,737,394 issued 1988 teaches an oil-absorbing article comprising a porous outer fabric of polyethylene or polypropylene which encloses fibrous oil absorbing particles. While the specification does not teach the recycling of the article, there is disclosed the hand wringing of the absorbed liquid from the article, and an indication that "the samples readily absorbed about an equal quantity of oil as was wrung out, even after the procedure was repeated several times...." (Col 7 Lines 3-6.)
U.S. Pat. No. 4,652,372 issued 1987 teaches an endless-belt type skimmer comprising an oleophilic belt and squeeze system for removing the hydrocarbons, and there are a number of these types of skimmers known in the art.
U.S. Pat. No. 4,497,72 issued 1985 teaches an absorbent pillow utilizing corn cob material for absorbing hydrocarbons, wherein the used pillow "may be utilized by a utility company or other type of company as fuel in a furnace....Alternatively, the pillow bay be used as land fill...."
U.S. Pat. No. 4,341,637 issued 1982 teaches an endless belt type skimmer wherein the oil is removed via pressurized steam applied to the belt.
As may be discerned from a review of the above, the prior art has failed to teach or contemplate a system for the economical and environmentally sound recycling of absorbent materials for absorbing liquid hydrocarbons and the like, and has at best suggested less destructive ways of disposing the used materials.
The '820 reference was the only patent to suggest any procedure for providing limited re-use of the absorbent, with that procedure limited only to the wringing out of the liquid. However, it is submitted that any re-use would appear to be limited, and without the results achieved in its first use. The '394 reference also discussed some hand wringing of the composition it claimed, but again it is submitted that wringing is insufficient to provide a re-useable system, as residue remains which is dirty, collects other contaminants, and may pose health and further environmental hazards during use. Further, it is averred that the absorption characteristics must and will be less with an unclean absorption material, effecting its performance.